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arXiv 1003.4883astro-ph.HE
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中子冷却盘驱动的伽马射线暴喷注进动

Jet Precession Driven by Neutrino-Cooled Disc for Gamma-Ray Bursts

Tong Liu, En-Wei Liang, Wei-Min Gu, Xiao-Hong Zhao, Zi-Gao Dai, Ju-Fu Lu

摘要:

为了解释伽马射线暴的时间结构和光谱演化,提出了一个由中微子冷却盘驱动的喷流进动模型。中微子主导的吸积盘外部的差速旋转可能导致吸积盘内部和中心黑洞的进动,从而通过中微子湮灭驱动吸积盘内部的进动喷流。我们的模型的分析和数值结果。我们的计算表明,具有黑洞质量$M \simeq 3.66 M_\odot$、吸积率$\dot{M} \simeq 0.54 M_\odot \rm s^{-1}$、自旋参数$a=0.9$和粘性参数$α=0.01$的黑洞-吸积盘系统可以驱动周期P=1 s、光度$L=10^{51}$ erg s $^{-1}$的旋进喷流,这与长GRB的情形相对应.具有$P=0.1$ s和$L=10^{50}$ erg s的旋进喷流可以由具有$M \simeq 5.59 M_\odot$、$\dot{M} \simeq 0.74 M_\odot \rm s^{-1}$、$a=0.1$和$α=0.01$的系统提供动力,这些系统可能是短伽玛暴的原因。我们的模型可以解释伽玛暴脉冲的时间和光谱演化。伽玛射线暴的中央发动机可能是由中微子冷却的圆盘驱动的旋进喷气机。因此,在GRB中心引擎的吸积时间尺度内,喷流进动可以调制全球GRB光变曲线。伽玛暴脉冲的时间和光谱演化都可能是由于喷注进动引起的观测效应。

英文摘要:

A model of jet precession driven by a neutrino-cooled disc around a spinning black hole is present in order to explain the temporal structure and spectral evolution of gamma-ray bursts (GRBs). The differential rotation of the outer part of a neutrino dominated accretion disc may result in precession of the inner part of the disc and the central black hole, hence drives a precessed jet via neutrino annihilation around the inner part of the disc. Both analytic and numeric results for our model are present. Our calculations show that a black hole-accretion disk system with black hole mass $M \simeq 3.66 M_\odot$, accretion rate $\dot{M} \simeq 0.54 M_\odot \rm s^{-1}$, spin parameter $a=0.9$ and viscosity parameter $α=0.01$ may drive a precessed jet with period P=1 s and luminosity $L=10^{51}$ erg s$^{-1}$, corresponding to the scenario for long GRBs. A precessed jet with $P=0.1$s and $L=10^{50}$ erg s$^{-1}$ may be powered by a system with $M \simeq 5.59 M_\odot$, $\dot{M} \simeq 0.74 M_\odot \rm s^{-1}$, $a=0.1$, and $α=0.01$, possibly being responsible for the short GRBs. Both the temporal and spectral evolution in GRB pulse may explained with our model. GRB central engines likely power a precessed jet driven by a neutrino-cooled disc. The global GRB lightcurves thus could be modulated by the jet precession during the accretion timescale of the GRB central engine. Both the temporal and spectral evolution in GRB pulse may be due to an viewing effect due to the jet precession.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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